1. Field of the Invention
The present invention relates to a rotation control device for a manually operated plying tool.
2. Description of the Related Art
U.S. Pat. No. 7,278,626 discloses an adjustable prying tool comprises a prying head, a handle and a checking mechanism. The prying head is perpendicularly connected to the handle, and has an arcuate body having a flat tipped front end and a lug at a rear end, whereas the handle has at front end a hexagon hole enabling to insert into the lug of the prying head. The lug has a circular depression in an upper portion including an internal stopping ring on the opposite side of the depression having a plurality of inverse radial teeth. The checking mechanism has a hexagon plate embedded into the hexagon hole of the handle including a stop ring having a plurality of positive radial teeth engageable with the plurality of inverse radial teeth of the internal stop ring of the prying head, an upper cover covers the circular depression of the lug and then engages with the hexagon plate, a lower cover screws with the lower portion of the lug, a resilient member is engaged between the hexagon plate and the lower cover to provide resilient force therein.
In normal condition, the plurality of positive radial teeth of the stop ring of the hexagon plate is pushed by the resilient member to engage with the plurality of inverse radial teeth of the internal stopping ring of the prying head, so the prying head and the handle are fixed relative to each other, and the angle therebetween is fixed and not adjustable.
When the plurality of positive radial teeth of the stop ring of the hexagon plate is disengaged from the plurality of inverse radial teeth of the internal stopping ring of the prying head by pressing the upper cover, the prying head can be rotated bidirectionally, and thus the angle between the prying head and the handle is adjustable.
When the abovementioned conventional prying tool is in use, its handle can be fixed or rotated with respect to the prying head. However, in actual practice, there is such a requirement for micro angle adjustment (such as 5 degrees) between the prying head and the handle, with the conventional structure, the user has to press the upper cover and then carry out adjustment appropriately, hence, not only is it impossible for the user to handle the prying tool with one hand, but the user to perform such micro angle adjustment is required to be experienced and skilled.
The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art.